The LS3 runs quieter than BigDog did, because it's meant to accompany squads in the field. Right now it's being tested to carry 180kg for 20 miles over 24 hours without being refueled, which should cut down on the 145kg-plus individual soldiers have to carry around.

I know the instinct is to play this forward into the Terminator scenarios, but these robots are staggeringly cool, and I absolutely want one to carry my stuff around if they ever make it down to the civillian level. [DARPA via IEEE]